Battle of the Bucket Brigade
I have been travelling during the summer, a long way from the metal walls of modular synths. But now I am back with monthly reports from the modular world.
Analogue Systems has during long time sold their RS-310 Reverb/Chorus, with a special multi tap bucket brigade chip capable to create electronic reverb effects.
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The length of the delay is controlled by the clock frequency. Normally, it is above 10 KHz, and filtered to be inaudible. For short delay times, the clock frequency is several hundred KHz. I tested three modules under the same conditions: The AS RS-310, a Doepfer A-188-1 with 128 steps to one with 2048 steps. In practice, it means that the delay time is from a dozen milliseconds in the 256 BBD Chip to up to over 200 milliseconds in the 4096 chip. The AS RS-310 is declared to be capable of up to 150 ms delay.
And here is the score:
Electronic reverb:
The RS-310 Reverb/Chorus is the winner, due to its pseudorandom multi tapped BBD. But it does not sound dramatic, even my old spring reverb outclasses it in most aspects. It is more of a sound colouring device than a reverb in my opinion.
Delay:
The Doepfer with the 2048 is, not unexpected, the best of the three modules. After adding a low pass filter to eliminate the clock frequency, it can create delays with a few hundred ms. But you have to accept a hard filtering, or noise will be heard as well as leak from the clock frequency. It is not like having Electro Harmonix Memory Man in the modular case, but it is usable. And the sound tends to be muddy and distant, just like the old Memory Man stompbox.
Karplus-Strong Synthesis:
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KS Synthesis is for me the major reason to have a BBD device in the modular setup. Varying the input, feedback level and clock frequency, sounds can be made that are impossible to get other ways. One note, though: As the 1V/Hz tracking is not so accurate, for exact scaled notes, it is necessary to make the melody line in a analogue sequencer, or use other devices to compensate the inaccurate scale tracking.
Chorus/Flanging:
Again, the Doepfer 256 step is the winner. It is richer and more subtle than the other modules. But if you want anything rougher, both Analogue Systems and Doepfer 4084 can do it. And with all patching of the Doepfer, the effects can be varied in a number of ways. Still, for “normal” and “elegant” effects in this area, more conventional equipment do it better.
Wave shaping:
All three of the modules can be used as a sort of wave shapers. The wildest is the Doepfer 2046 that really can scream if you want it to. In the AS module, some of the edge is lost due to the internal low pass filter. But there are in all three modules there is lot of fun sounds to be found.
It is in the area of sound manipulation and sound creation the real strength of the BBD devices is shown. Some of the rough and strange sounds it can make are hard to get in any other way. The wave shaping capacity is underlined in the Doepfer modules with a polarity switch that can turn a saw tooth input to a square wave, or do other tricks. It has also a separate feedback input, so the sound can be processed in other modules before it re-enters the module.
Versatility:
The concept of the AS and Doepfer are quite different. The AS module is rather straight forward, with a low pass filter in the signal chain. The Doepfer is made for the experimentalist, with 10 jacks for signals and CV. There is no internal low pass filter, neither any limits for the high speed vco that makes the clock frequency. It is even possible to use the the HS VCO output, that gives in frequencies from normal audio to notes far beyond 20 KHz. In a ring modulator, it gives sounds reminding on tuning an old AM radio.
Value for money:
At the factory price list (including local VAT), the AS 310 is just under USD 230. The Doepfer modules vary from USD 153 to USD 204, depending on the price of the BBD chip. And in nearly all of the aspects, the Doepfer is the winner of the Battle of the Bucket Brigades. To choose between the 256 and 2048 chips is a harder question. I would vote for the 2048, as it sounds rougher when it is driven into distortion and in Karplus-Strong synthesis. But it is a question of taste.
Anyhow, everything under the sun is not BBD chips. There is a whole array of new modules on the way:
Metalbox, http://www.metalbox.com/ , continuities their series of Frack Rack modules. Really interesting sound samples comes from their new Wave Multiplier. It consists of three independent and different circuits that adds overtones, all controlled by CV. The prize is USD 300 and it looks like a really nice tone bender. I actually think of buying one for my own setup. Bit-N-Tic is their name on a new comb/all pass filter, suitable for phasing, filtering or as a VCO when in self oscillation. It can also perform as distortion unit, claims the firm. Prize is USD 325.
A sort of new veteran on the arena is Bananalogue with the legendary constructor Serge Tcherepnin as one of the men behind. They offer two modules, sketched from the old Serge modular. Serge WVX is a wave multiplier, with one independent Lockarhart wave folder, and one full wave rectifier. Price is USD 275 for both Frack Rack and Eurorack format. Sound samples can be found on http://www.bananalogue.com/ They have also another module for sale, the Serge VCS. It is an advanced slew limiter that can do more things than just glide. Due to its construction, it can work as a LFO, VC envelope generator, audio divider and even VCO and pulse delay. The prize is pretty fair, USD 195.With their experimental orientated modules, I think they are more than welcome into the modular world.
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A-1 is an audio interface, with balances XLR connections. A-2 is an audio interface, with an opto compressor and envelope follower. There is also a voltage controllable compressor on the way, the VCFC. I have never heard of modules like that before.
PH4 is a barber pole generator. It gives four separate LFO outputs with a phase shift of 45 degrees. Used for feeding four filters, VCOs or phasers it gives an illusion of infinite rising frequency. I guess it is supposed to be used with two of Cwejmans SPH2, a dual (or stereo) 14 step phaser.
The Cwejman idea is to put many functions in each module, and have several pre patched internal connections, a bit like a semi modular module. One of the new units, the FSH-1, is for example, a frequency shifter, but also a ring modulator with an internal carrier generator. As the internal VCO can go down to LFO area, it can also work as a panning device.
There are also a voltage processor, a dual filter module and a dual VCA module in the new Cwejman series. Prize or date of release in not known right now.
Cwejman also plans to release a 19” rack of his own. The Cwejman modules are compatible with Eurorack, but as the printed board is parallel to the front plate, the depth is only a few centimetres. So the Cwejman rack will be a slim construction, possible to use as a desktop unit. I think it is a smart idea, as the main ingredient in all mighty modulars is just air…
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Finally, Magic Smoke Electronics , http://www.magsmoke.com/products.asp , is a new star in the modular galaxy. There first module is a filter with four outputs, phase shifted in 45 degrees. Yet, only the PCB board is available, but complete kits for soldering guys are on the way. Magic Smoke has, by the way, nothing to do with stimulant herbs. It is a DIY joke. When a component is burned by wrong voltage, there is smoke coming out from the gear. Or at least a distinct smell of over heated plastic. So the thing is to keep the magic smoke inside the electronics. I have seen the magic smoke several times myself, and it is not what you want from your precious modules.
